In the oil and gas well drilling industry, downhole temperature logs are useful for formation evaluation and for interpreting downhole conditions during drilling operations, well completion, and/or reservoir and production monitoring. One option for collecting a downhole temperature log involves deploying sensors that rely on electrical power to sense temperature and/or to convey a temperature reading to a storage media downhole or at earth's surface. Another option for collecting a downhole temperature log involves deploying a fiber optic cable (distributed temperature sensing). In a drilling environment, maintaining a continuous electrical or optical transmission line is problematic due to issues such as the segmented manner in which drill strings are formed, the drill string twisting and contacting the borehole wall, and space constraints. While use of a portable electrical power source (e.g., batteries) could enable collection of a downhole temperature log without a continuous electrical or optical transmission line, the high temperatures in the downhole environment often degrade or prevent use of a portable electrical power source.
It should be understood, however, that the specific embodiments given in the drawings and detailed description thereto do not limit the disclosure. On the contrary, they provide the foundation for one of ordinary skill to discern the alternative forms, equivalents, and modifications that are encompassed together with one or more of the given embodiments in the scope of the appended claims.